Comparative sequence work which uncovers conserved regions of nucleic acid has been and will continue to be an important element in recognizing functional sites on rRNA. We will do comparative sequence work on a region near the 3' end of 16S rRNA which appears to be a "suface" component of 30S ribosomes. This region is also at the interface between 30S and 50S ribosomes. We will also do additional sequence work on eukaryotic 18S rRNA and small ribosomal subunit RNA of mitochondria and chloroplasts to determine what sequences are possibly used in eukaryotic systems to carry out various ribosome functions. We do standard RNA sequencing by the methods originally devised by Sanger and associates. We also do RNA sequencing by converting RNA into a complementary copy of DNA, using a specific primer and AMV reverse trancriptase. The cDNA is then sequenced by the methods of Maxam and Gilbert.